The present invention generally relates to material handling bucket structures and, in a preferred embodiment thereof, more particularly relates to a specially designed reinforced bucket structure for use with a loader vehicle such as a wheeled loader.
A conventionally constructed loader bucket used in earth working operations is typically attached to the lower end of a lift arm which, in turn, is operatively connected to a wheeled loader. This type of loader bucket is of a rugged, all-metal construction, with an open front side, and has a bottom wall (referred to in the industry as a "lip"). The front side edge of the lip has a spaced series of forwardly projecting adapter structures to which replaceable digging tooth points may be removably connected, and the lip has a straight rear side edge. A curved, relatively thin rear side wall of the bucket is positioned opposite its open front side. Extending rearwardly from the straight rear side edge of the lip is a multi-piece rear bottom wall structure, with edge portions of the individual pieces of the bottom wall structure being welded to the rear side edge of the lip.
Secured to the curved rear side wall of the loader bucket, and extending rearwardly therefrom, are two or more pairs of lifting ears which are spaced apart from each other in a direction parallel to the rear side edge of the bucket lip. The lifting ear pairs are positioned on opposite sides of a pair or more of tilt ears which are also secured to he curved rear side wall of the loader bucket and extend rearwardly therefrom. The lifting ear pairs, and the tilt ears disposed therebetween, are pivotally connected by pins to the lift arm, with the two pairs of lifting ears being used to lift and lower the bucket relative to the ground, and the central tilt ears being used to selectively pivot the bucket about the lifting ear pins during earthworking use of the loader bucket.
In a conventionally constructed loader bucket of this general type, bottom side portions of the lifting ears are secured to the rear side wall of the bucket and the rear side edge of the lip, but the tilt ears are secured only to the curved rear side wall of the bucket at points spaced well rearwardly of the rear side edge of the bucket lip.
Two primary problems are presented by this conventional loader bucket construction. First, because of the many separate pieces used to form the rear bottom wall structure, the bucket is tedious and relatively expensive to manufacture. Second, particularly during the exertion of "prying" forces on the bucket (i.e., forcibly pivoting the bucket rearwardly and upwardly while a front portion of its lip is embedded in the earth), the previously described conventional connection of the lifting and tilt ears to the balance of the bucket structure tends to cause premature cracking failure along a bottom side portion of the bucket generally aligned with the tilt ears--usually along a crack line transverse to the rear side edge of the bucket lip.
As can be seen from the foregoing, a need exists for an improved loader bucket construction which eliminates or at least substantially reduces the above-mentioned problems associated with conventionally constructed loader buckets of the general type described. It is to this need to which the present invention is directed.